this pointer
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Intérieur de la fonction membre non statique, contient un pointeur vers l'objet de classe à partir de laquelle la fonction a été appelée .
Original:
Inside non-static member function, holds a pointer to the class object from which the function was invoked.
The text has been machine-translated via Google Translate.
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Le type de pointeur est
this cv T* const où T est le nom de la classe et cv se réfère à la prescripteurs cv de la fonction du pointeur est utilisé po Par exemple:Original:
The type of
this pointer is cv T* const where T is the class name and cv refers to the prescripteurs cv of the function the pointer is used in. For example:The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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| Function signature | Type of this
|
|---|---|
void T::foo()
|
T* const this;
|
void T::foo() const
|
const T* const this;
|
void T::foo() volatile
|
volatile T* const this;
|
void T::foo() const volatile
|
const volatile T* const this;
|
Exemple
class T
{
int x;
void foo()
{
this->x = 5; // this used explicitly
x = 6; // same as this->x = 6;
}
void foo() const
{
this->x = 7; // Error: *this is constant
}
void foo ( int x )
{
// parameter x shadows the attribute with the same name
this->x = x; // unqualified x refers to the parameter, but the attribute is still accessible using the this pointer
}
T& operator= ( const T& b )
{
x = b.x;
return *this; // this is often used when a reference to the current object is needed
}
void bar ( const T& b )
{
// two ways to call class operators using this
(*this) = b;
this->operator= ( b );
}
void bar()
{
// methods can be called even when there's no object
// the this pointer can be seen like an additional parameter implicitly passed
if ( this == NULL )
return;
}
};
T* pointer = reinterpret_cast<T*>(123);
pointer->bar(); // bar is called with 123 (0x7B) as value for this